Way to go, Ratte! A true 800x600 mode at last would be great, especially for those 020+ Indivision ECS owners.
On another note, was HighGFX Extreme ever finished and usable? I remember testing it unsuccessfully, but perhaps it was because my Indivision hadn't been flashed to the latest firmware yet.
Keep up the good work! 
I heard that it was finished ages ago, just waiting for Oliver to update the FPGA (seems to be a bit slow).